Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
Key Laboratory of Three Gorges Reservoir Region's Eco-environment, Ministry of Education, Chongqing University, Chongqing 400045, China; State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China.
Environ Int. 2024 Jul;189:108812. doi: 10.1016/j.envint.2024.108812. Epub 2024 Jun 11.
The linkage between biocides and antibiotic resistance has been widely suggested in laboratories and various environments. However, the action mechanism of biocides on antibiotic resistance genes (ARGs) spread is still unclear. Thus, 6 quaternary ammonium biocides (QACs) with different bonded substituents or alkyl chain lengths were selected to assess their effects on the conjugation transfer of ARGs in this study. Two conjugation models with the same donor (E. coli DH5α (RP4)) into two receptors, E. coli MG1655 and pathogenic S. sonnei SE6-1, were constructed. All QACs were found to significantly promote intra- and inter-genus conjugative transfer of ARGs, and the frequency was highly impacted by their structure and receptors. At the same environmental exposure level (4 × 10 mg/L), didecyl dimethyl ammonium chloride (DDAC (C10)) promoted the most frequency of conjugative transfer, while benzathine chloride (BEC) promoted the least. With the same donor, the enhanced frequency of QACs of intra-transfer is higher than inter-transfer. Then, the acquisition mechanisms of two receptors were further determined using biochemical combined with transcriptome analysis. For the recipient E. coli, the promotion of the intragenus conjugative transfer may be associated with increased cell membrane permeability, reactive oxygen species (ROS) production and proton motive force (PMF)-induced enhancement of flagellar motility. Whereas, the increase of cell membrane permeability and decreased flagellar motility due to PMF disruption but encouraged biofilm formation, maybe the main reasons for promoting intergenus conjugative transfer in the recipient S. sonnei. As one pathogenic bacterium, S. sonnei was first found to acquire ARGs by biocide exposure.
杀菌剂与抗生素抗性之间的联系在实验室和各种环境中已被广泛提出。然而，杀菌剂对抗生素抗性基因（ARGs）传播的作用机制仍不清楚。因此，本研究选择了 6 种具有不同键合取代基或烷基链长度的季铵盐杀菌剂（QACs），以评估它们对 ARGs 转移的影响。本研究构建了两个具有相同供体（E. coli DH5α（RP4））的接合模型，分别进入两个受体，E. coli MG1655 和致病性 S. sonnei SE6-1。所有 QACs 均显著促进了 ARGs 的种内和种间接合转移，其频率受结构和受体的高度影响。在相同的环境暴露水平（4×10mg/L）下，二癸基二甲基氯化铵（DDAC（C10））促进了最高的接合转移频率，而苯扎氯铵（BEC）促进的频率最低。对于相同的供体，QAC 对内转移的增强频率高于外转移。然后，使用生化结合转录组分析进一步确定了两个受体的获取机制。对于受体 E. coli，种内接合转移的促进可能与增加细胞膜通透性、活性氧（ROS）产生和质子动力势（PMF）诱导的鞭毛运动增强有关。而由于 PMF 破坏导致细胞膜通透性增加和鞭毛运动减弱，但促进生物膜形成，可能是促进受体 S. sonnei 种间接合转移的主要原因。作为一种致病性细菌，首次发现 S. sonnei 通过接触杀菌剂获得 ARGs。
